It's an issue with WhileMatchFilter. I've created issue HBASE-2258... On 24 February 2010 18:25, Ryan Rawson <ryano...@gmail.com> wrote:
> That is very interesting, there are definitely some hidden performance > landmines in the filter code... you have clearly found one. > > strange in that while match filter is just a thin wrapper. > > > > On Tue, Feb 23, 2010 at 11:22 PM, Dan Washusen <d...@reactive.org> wrote: > > OK, a bit more info; removing the WhileMatchFilter drops the scans down > to > > 25ms each. > > > > Updated scan looks like: > > > >> Scan scan = new Scan(getRandomRow(this.rand, this.totalRows)); > >> > >> scan.addColumn(FAMILY_NAME, QUALIFIER_NAME); > >> > >> scan.setFilter(new PageFilter(120)); > >> > >> > > The slow scan uses: > > > >> Scan scan = new Scan(getRandomRow(this.rand, this.totalRows)); > >> > >> scan.addColumn(FAMILY_NAME, QUALIFIER_NAME); > >> > >> scan.setFilter(new *WhileMatchFilter*(new PageFilter(120))); > >> > >> > > > > > > On 24 February 2010 18:17, Dan Washusen <d...@reactive.org> wrote: > > > >> Hey All, > >> While testing the recent MemStoreScanner slowness I noticed that each > scan > >> in the randomSeekScan test takes about 19 seconds to complete. The scan > in > >> question provides a startRow and a WhileMatchFilter containing a > PageFilter > >> that asks for 120 rows. I would have expected this scan to return in > >> roughly the same amount of time as a scan that specifies a startRow and > >> stopRow that spans a similar number of rows. > >> > >> Before I start investigating further I was wondering if anyone had any > >> thoughts? > >> > >> Cheers, > >> Dan > >> > >> p.s. Running the test on the latest 0.20 code... > >> > > >
